A cooling device, system, and method for cryogenic acoustic pressure calibration of pressure sensors.

Abstract

This invention discloses a cooling device, system, and method for low-temperature acoustic pressure calibration of a pressure sensor, comprising a pressure sensor to be calibrated and a thermocouple, a sensor mounting component, a cold bridge, a cold storage component, an insulation layer, a reflective layer, and a cold window. The thermocouple is bonded between the pressure sensor to be calibrated and the sensor mounting component. The cold storage component has structures for attaching to a spatial positioning device of the calibration sensor and for attaching the cold bridge. The cold bridge is fixed to the cold storage component and has a structure for attaching the sensor mounting component. The sensor mounting component is fixed to the cold bridge and has a structure for mounting the pressure sensor to be calibrated. The insulation layer covers the outer surfaces of the cold storage component, the cold bridge, and the sensor mounting component, as well as the outer surface of the pressure sensor to be calibrated, excluding the working surface. A notch for contacting the refrigerant is left on the surface of the cold storage component, serving as a cold window. The reflective layer covers the outer surface of the insulation layer and does not obstruct the cold window. During cooling, the refrigerant is poured onto the cold storage component through the cold window.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sound pressure calibration of pressure sensors, and particularly relates to a cooling device, system and method for sound pressure calibration of pressure sensors at low temperature. BACKGROUND

[0002] Sound pressure calibration, as a non-contact pressure calibration method, has important applications in pressure sensor calibration. In order to ensure that the calibration is not disturbed by the reflection from the wall, sound pressure calibration is generally carried out in a chamber with sound-absorbing structures (such as sound-absorbing cones) on the wall. When the low-temperature performance of the sensor needs to be calibrated, the experimental scheme needs to ensure that the sensor can be reduced to a sufficient temperature and the temperature rise is slow enough to ensure that the data obtained from the experiment can correctly reflect the performance of the sensor at the measured temperature. However, although a general thermostat can ensure temperature regulation, its inner wall does not have sound-absorbing structures and cannot meet the acoustic requirements of sound pressure calibration. If a general sound-absorbing chamber is modified to have cooling function, considering that the sound-absorbing chamber needs to accommodate a complete set of acoustic measurement equipment (including at least acoustic power output equipment and sensor spatial positioning equipment in principle), as well as the installation space of the wall sound-absorbing structure, its volume cannot be very small, and it is difficult to achieve economical refrigeration when the low-temperature requirement is high (such as close to-100℃).

[0003] If the sensor is cooled separately and placed in a general sound-absorbing chamber for experiment, since the pressure sensor is usually small in size, its thermal inertia is also low, and it heats up quickly in a room temperature environment, it is difficult to ensure sufficient test time and difficult to ensure that certain test data can correctly reflect the performance of the sensor at the corresponding test temperature. SUMMARY

[0004] In order to overcome the deficiencies in the prior art, the present application provides a cooling device, system and method for sound pressure calibration of pressure sensors at low temperature.

[0005] In order to achieve the above application purposes and solve the technical problems, the technical solutions adopted are as follows:

[0006] The present application discloses a cooling device for sound pressure calibration of pressure sensors at low temperature, comprising a to-be-calibrated pressure sensor and a thermocouple, a sensor mounting member, a cold bridge, a cold storage member, a thermal insulation layer, a reflective layer and a cold window, wherein:

[0007] The thermocouple is bonded between the to-be-calibrated pressure sensor and the sensor mounting member;

[0008] The cold storage member has a structure for attaching a calibration sensor spatial positioning device and a structure for attaching the cold bridge, for storing cold energy;

[0009] The cold bridge is fixed to the cold storage component. The cold bridge has a structure for the sensor mounting component to attach to. The end of the cold bridge connected to the cold storage component is the cold end of the cold bridge, and the end connected to the sensor mounting component is the hot end of the cold bridge, which is used to form a temperature gradient from the cold end to the hot end of the cold bridge.

[0010] The sensor mounting component is fixedly connected to the cold bridge, and the sensor mounting component has a structure for mounting the pressure sensor to be calibrated.

[0011] The insulation layer firmly and completely covers the outer surface of the cold storage component, the cold bridge, and the sensor mounting component, as well as the outer surface of the pressure sensor to be calibrated, excluding the working surface, and is used for insulation of the cold storage component and the thermal bridge.

[0012] A notch is left on the surface of the cold storage component for contact with the refrigerant; the area of ​​the surface of the cold storage component that is not covered by the insulation layer is a cold window.

[0013] The reflective layer completely covers the outer surface of the insulation layer and does not block the cold window;

[0014] When the refrigerant is used for cooling, it is poured onto the cold storage component through the cold window.

[0015] Furthermore, the cold window is located away from the installation position of the cold bridge and is designed to face upwards to avoid convective heat transfer with the air.

[0016] Furthermore, the outer normal of the cold window is vertically upward to prevent the surface from forming a natural convection heat transfer surface and accelerating the loss of cold energy.

[0017] Preferably, the cold bridge is a round bar made of 304 stainless steel, which has poor thermal conductivity among common metallic materials.

[0018] Preferably, the cold storage component is a cuboid made of aluminum alloy 3011, which has high thermal conductivity among common metals.

[0019] Preferably, the insulation layer is a sponge.

[0020] Preferably, the reflective layer is made of aluminum foil.

[0021] This invention also discloses a low-temperature sound pressure calibration system for pressure sensors, comprising the aforementioned cooling device, a sensor to be calibrated and a temperature sensor, a sensor spatial positioning device, and a sound pressure generating device, wherein:

[0022] The cooling device is thermally insulated and fixedly connected to the sensor spatial positioning device;

[0023] The sensor to be calibrated and the temperature sensor are firmly bonded to the sensor mounting component of the cooling device with good heat transfer.

[0024] The sound pressure generating device is fixedly connected to the sensor spatial positioning device, and the sensor spatial positioning device maintains a relatively stable position between it and the sensor to be calibrated and the temperature sensor.

[0025] This invention also discloses a cooling method for cryogenic acoustic pressure calibration of pressure sensors, which uses the aforementioned cooling device and includes the following steps:

[0026] Step A1: The sensor to be calibrated and the temperature sensor are installed on the sensor mounting component of the cooling device, and together with the sensor spatial positioning device, they are placed in the anechoic chamber.

[0027] Step A2: Continue pouring refrigerant into the cold window area;

[0028] Step A3: Monitor the temperature of the working surface of the sensor to be calibrated, and stop pouring refrigerant when it reaches a value lower than the target temperature;

[0029] Step A4: Exit and close the anechoic chamber, turn on the sound pressure generating device, continuously monitor the working surface temperature of the sensor to be calibrated, and collect the output value of the pressure sensor to be calibrated when the target temperature is reached.

[0030] By employing the above technical solutions, this invention has the following advantages and positive effects compared with the prior art:

[0031] This invention utilizes a pair of materials with different thermal transfer properties as a cold storage component and a cold bridge. A refrigerant cools a point in the cold storage component far from the cold bridge, creating a temperature gradient from the cold window to the pressure sensor to be calibrated. The large temperature gradient between the hot and cold ends of the cold bridge, due to its poor thermal conductivity, allows the cold storage component to reach a lower temperature when the sensor reaches near the target temperature. Combined with the large volume and heat capacity of the cold storage component, it can store a significant amount of cold energy. When the working surface of the pressure sensor heats up due to contact with room temperature air, the heat transfer coefficient from the cold end to the hot end of the cold bridge is greater than the heat transfer coefficient between the surface and the air. The cold energy stored in the cold storage component can be continuously transferred to the pressure sensor through the cold bridge, slowing down its temperature rise and thus meeting the requirements for gradual temperature change testing. This invention is low-cost, simple and convenient to operate, and has good versatility. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0033] Figure 1 This is a schematic diagram of a cooling device for low-temperature acoustic pressure calibration of a pressure sensor provided in Embodiment 1 of the present invention;

[0034] Figure 2 This is a schematic diagram of a low-temperature acoustic pressure calibration system for a pressure sensor provided in Embodiment 2 of the present invention;

[0035] Figure 3 This is a comparison chart showing the effects of using the low-temperature acoustic pressure calibration system for pressure sensors provided in Example 2 with and without the present invention.

[0036] [Explanation of Key Symbols]

[0037] 1-Cooling device; 11-Pressure sensor and thermocouple to be calibrated; 12-Sensor mounting components; 13-Cold bridge; 14-Cold storage components; 15-Insulation layer; 16-Reflective layer; 17-Cold window;

[0038] 2- Sensors to be calibrated and temperature sensors;

[0039] 3-Sensor spatial positioning device;

[0040] 4-Sound pressure generating device. Detailed Implementation

[0041] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] Example 1

[0045] like Figure 1 As shown, this invention discloses a cooling device for low-temperature acoustic pressure calibration of a pressure sensor, comprising a pressure sensor to be calibrated and a thermocouple 11, a sensor mounting component 12, a cold bridge 13, a cold storage component 14, a thermal insulation layer 15, a reflective layer 16, and a cold window 17, wherein:

[0046] The thermocouple is bonded between the pressure sensor to be calibrated and the sensor mounting component 12;

[0047] The cold storage component 14 is made of a material with high thermal conductivity and large heat capacity. It has a structure for attaching to the calibration sensor spatial positioning device 3 and a structure for attaching the cold bridge 13, for storing cold energy. In this embodiment, the geometric dimensions should be as large as possible to store as much cold energy as possible.

[0048] The cold bridge 13 is made of a material with appropriate thermal conductivity and is fixed to the cold storage component 14 by means of good thermal conductivity. The cold bridge 13 has a structure for the sensor mounting component 12 to attach to. The end of the cold bridge 13 connected to the cold storage component 14 is the cold end of the cold bridge, and the end connected to the sensor mounting component 12 is the hot end of the cold bridge, which is used to form a temperature gradient from the cold end to the hot end of the cold bridge. In this embodiment, the thermal conductivity of the material of the cold bridge 13 should be significantly less than that of the material of the cold storage component 14, so as to facilitate the formation of a temperature gradient from the cold end to the hot end of the cold bridge during the cooling stage. At the same time, the heat transfer coefficient between the cold end and the hot end of the cold bridge should be significantly greater than the heat transfer coefficient of the sensor working surface, so as to ensure that the cold energy lost from the sensor working surface can be replenished by the cold storage component 14. Preferably, after the material of the cold bridge 13 is selected, the heat transfer coefficient between the cold end and the hot end of the cold bridge can be adjusted by adjusting its cross-sectional and length dimensions.

[0049] The sensor mounting component 12 is fixedly connected to the cold bridge 13. The sensor mounting component 12 has a structure for mounting the pressure sensor to be calibrated. In this embodiment, the shape of the sensor mounting component 12 is not limited, but it should be able to stably connect the sensor to be calibrated and the cold bridge 13 and provide good thermal conductivity.

[0050] The insulation layer 15 is made of a material with poor thermal conductivity and firmly and completely covers the outer surfaces of the cold storage component 14, the cold bridge 13, and the sensor mounting component 12, as well as the outer surface of the pressure sensor to be calibrated, excluding the working surface, for insulation of the cold storage component 14 and the thermal bridge. In this embodiment, the shape and material of the insulation layer 15 are not limited, but it should have sufficient thickness to maintain the thermal insulation performance of the covered area. In this example, sponge is selected as the material of the insulation layer 15, and its thickness is 10 mm.

[0051] A notch is left on the surface of the cold storage component 14 for contact with the refrigerant. The surface area of ​​the cold storage component 14 that is not covered by the insulation layer 15 is called the cold window 17.

[0052] The reflective layer 16 is made of a material with low thermal emissivity and completely covers the outer surface of the insulation layer 15 without obstructing the cold window 17. In this embodiment, the shape and material of the reflective layer 16 are not limited. Considering that the power of heat conduction through radiation is proportional to the fourth power of temperature, when the target temperature is significantly lower than the temperature of this device, the radiative heat input of the environment to this device will be very significant. Therefore, the reflective layer 16 should have a sufficiently high reflectivity. In this example, aluminum foil is selected as the material of the reflective layer 16.

[0053] The refrigerant is a liquid with a boiling temperature below the required calibrated temperature under normal pressure, and is poured onto the cold storage component 14 through the cold window 17 during refrigeration.

[0054] Furthermore, the cold window 17 is positioned away from the installation location of the cold bridge 13 and is designed to face upwards to prevent convective heat transfer with the air, thereby facilitating sufficient cooling of the material between the cold window 17 and the hot end of the cold bridge in the cold storage component 14. In this embodiment, the shape of the cold window 17 is not limited, as long as it is positioned as far away from the installation location of the cold bridge 13 as possible.

[0055] Furthermore, the outer normal of the cold window 17 is vertically upward to prevent the surface from forming a natural convection heat transfer surface and accelerating the loss of cold energy.

[0056] Preferably, the cold bridge 13 is a round bar made of 304 stainless steel, a common metallic material with relatively poor thermal conductivity, with a length of 50 mm and a diameter of 5 mm. In this embodiment, the material properties and shape of the cold bridge 13 have a significant impact on the actual effect of the device.

[0057] Preferably, the cold storage component 14 is a cuboid made of aluminum alloy 3011, which has high thermal conductivity among common metals, with geometric dimensions of 100mm in length, 60mm in height, and 30mm in thickness. In this embodiment, there are no restrictions on the shape and material of the cold storage component 14, but it should have a large heat capacity, high thermal conductivity, and large volume.

[0058] Example 2

[0059] Please refer to Figure 2 This embodiment provides a low-temperature sound pressure calibration system for pressure sensors, as an application scenario of Embodiment 1 of the present invention. It includes the aforementioned cooling device 1, the sensor to be calibrated and the temperature sensor 2, the sensor spatial positioning device 3, and the sound pressure generating device 4, wherein:

[0060] The cooling device 1 is thermally insulated and fixedly connected to the sensor spatial positioning device 3;

[0061] The sensor to be calibrated and the temperature sensor 2 are firmly bonded to the sensor mounting component 12 of the cooling device 1 with good heat transfer.

[0062] The sound pressure generating device 4 is fixedly connected to the sensor spatial positioning device 3, and the sensor spatial positioning device 3 maintains a relatively stable position between it and the sensor to be calibrated and the temperature sensor 2.

[0063] When the device is in operation, the entire device is placed in an anechoic chamber. The sound pressure generating device 4 provides a sound pressure load at a known intensity. The sensor spatial positioning device 3 maintains a stable relative position with the sensor to be calibrated and the temperature measuring sensor 2. By collecting the feedback data of the sensor to be calibrated and the temperature measuring sensor 2, the relationship between the input and output of the pressure sensor to be calibrated at the current temperature can be obtained, thereby completing the calibration.

[0064] Example 3

[0065] The cooling device 1 for low-temperature acoustic pressure calibration of the pressure sensor is used to cool the sensor to be calibrated and the temperature sensor 2 in the above calibration work and to ensure that their temperature rises at the designed rate. The method of using the cooling device 1 includes the following steps:

[0066] Step A1: The sensor to be calibrated and the temperature sensor 2 are installed on the sensor mounting component 12 of the cooling device 1, and together with the sensor spatial positioning device 3, they are placed in the anechoic chamber.

[0067] Step A2: Continuously pour refrigerant into the cold window 17;

[0068] Step A3: Monitor the temperature of the working surface of the sensor to be calibrated, and stop pouring refrigerant when it reaches a value lower than the target temperature;

[0069] Step A4: Exit and close the anechoic chamber, turn on the sound pressure generating device, continuously monitor the working surface temperature of the sensor to be calibrated, and collect the output value of the pressure sensor to be calibrated when the target temperature is reached.

[0070] To demonstrate the effectiveness of Embodiment 3, this embodiment also provides a cooling step without the aforementioned cooling device, for comparison with the cooling and temperature control effects using the aforementioned cooling device 1. Figure 3 As shown:

[0071] Step B1: The sensor to be calibrated and the temperature sensor 2 are installed on the sensor spatial positioning device 3, and together with the sound pressure generating device, are placed in the anechoic chamber;

[0072] Step B2: Continuously pour refrigerant onto the sensor to be calibrated and temperature sensor 2;

[0073] Step B3: Monitor the temperature of the working surface of the sensor to be calibrated, and stop pouring refrigerant when it reaches a value lower than the target temperature;

[0074] Step B4: Exit and close the anechoic chamber, turn on the sound pressure generating device, continuously monitor the working surface temperature of the sensor to be calibrated, and collect the output value of the pressure sensor to be calibrated when the target temperature is reached.

[0075] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cooling device for low temperature acoustic pressure calibration of a pressure sensor, characterized in that, The application relates to a calibration device for pressure sensor, which comprises a pressure sensor to be calibrated, a sensor mounting member, a cold bridge, a cold storage member, a heat insulation layer, a reflective layer and a cold window. The thermocouple is adhered between the pressure sensor to be calibrated and the sensor mounting member. The cold storage member is provided with a structure for attaching the sensor space positioning device and a structure for attaching the cold bridge, and is used for storing cold energy. The cold bridge is fixed to the cold storage member, and the cold bridge is provided with a structure for attaching the sensor mounting member. The sensor mounting member is fixed to the cold bridge, and the sensor mounting member is provided with a structure for mounting the pressure sensor to be calibrated. The heat insulation layer is firmly and integrally wrapped on the outer surfaces of the cold storage member, the cold bridge and the sensor mounting member, and the outer surfaces of the pressure sensor to be calibrated except the working surface, and is used for heat insulation of the cold storage member and the cold bridge. An opening is left on the surface of the cold storage member for contacting the refrigerant, and the surface area of the cold storage member not wrapped by the heat insulation layer is the cold window. The reflective layer is integrally wrapped on the outer surface of the heat insulation layer and does not block the cold window. The refrigerant is poured on the cold storage member through the cold window when the refrigerant is refrigerated. The cold window is away from the mounting position of the cold bridge, and the opening is upward, so that the convection heat exchange with air is avoided.

2. The cooling device for low-temperature acoustic calibration of a pressure sensor according to claim 1, characterized in that The outer normal of the cold window is vertically upward, so that the surface is prevented from forming a natural convection heat exchange surface and the loss of cold energy is accelerated.

3. The cooling device for low temperature acoustic calibration of pressure sensors according to claim 1, characterized in that, The cold storage member is an aluminum alloy 3011 cuboid.

4. The cooling device for low temperature acoustic calibration of pressure sensors according to claim 1, characterized in that, The heat insulation layer is sponge.

5. The cooling device for low temperature acoustic calibration of pressure sensors according to claim 1, characterized in that, The reflective layer is aluminum foil.

6. The cooling device for low temperature acoustic calibration of pressure sensors according to claim 1, characterized in that, The application further relates to a cooling device, a sensor to be calibrated, a sensor space positioning device and a sound pressure generating device.

7. A system for low temperature acoustic pressure calibration of a pressure sensor, comprising: The cooling device is fixed to the sensor space positioning device. The sensor to be calibrated is firmly adhered to the sensor mounting member of the cooling device. The sound pressure generating device is fixed to the sensor space positioning device and is kept in a stable position between the sensor to be calibrated and the sensor space positioning device. The application further relates to a cooling method using the cooling device.

8. A cooling method for low temperature acoustic pressure calibration of a pressure sensor, characterized in that, A1: the sensor to be calibrated is mounted on the sensor mounting member of the cooling device and the sensor space positioning device, and is placed in a soundproof room together with the sound pressure generating device; A2: the refrigerant is continuously poured on the cold window; A3: the temperature of the working surface of the sensor to be calibrated is monitored, and the pouring of the refrigerant is stopped when the temperature is lower than a target temperature value; and A4: the soundproof room is exited and closed, the sound pressure generating device is opened, the temperature of the working surface of the sensor to be calibrated is continuously monitored, and the output value of the sensor to be calibrated is collected when the temperature reaches the target temperature.

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